Reduced binding activity of vaccine serum to omicron receptor-binding domain.

Coronavirus disease 2019 (COVID-19) vaccination regimens contribute to limiting the spread of severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2). However, the emergence and rapid transmission of the SARS-CoV-2 variant Omicron raise a concern about the efficacy of the current vaccination strategy. Here, we expressed monomeric and dimeric receptor-binding domains (RBDs) of the spike protein of prototype SARS-CoV-2 and Omicron variant in E. coli and investigated the reactivity of anti-sera from Chinese subjects immunized with SARS-CoV-2 vaccines to these recombinant RBDs. In 106 human blood samples collected from 91 participants from Jiangxi, China, 26 sera were identified to be positive for SARS-CoV-2 spike protein antibodies by lateral flow dipstick (LFD) assays, which were enriched in the ones collected from day 7 to 1 month post-boost (87.0%) compared to those harvested within 1 week post-boost (23.8%) (P < 0.0001). A higher positive ratio was observed in the child group (40.8%) than adults (13.6%) (P = 0.0073). ELISA results showed that the binding activity of anti-SARS-CoV-2 antibody-positive sera to Omicron RBDs dropped by 1.48- to 2.07-fold compared to its homogeneous recombinant RBDs. Thus, our data indicate that current SARS-CoV-2 vaccines provide restricted humoral protection against the Omicron variant.

ASPM and TROAP gene expression as potential malignant tumor markers.

Background: Although increasing evidence supports a vital role for assembly factor for spindle microtubules (ASPM) and trophinin-associated protein (TROAP) in the tumorigenesis of some cancers, no systematic pancancer analyses of ASPM and TROAP have been performed. Thus, we aimed to investigate the potential functions of ASPM and TROAP across 31 cancer types. Methods: Based on datasets from The Cancer Genome Atlas (TCGA), Human Protein Atlas (HPA), Gene-Cloud of Biotechnology Information (GCBI) and Gene Expression Omnibus (GEO), we employed an array of bioinformatics methods to explore the potential oncogenic roles of ASPM and TROAP. Results: ASPM and TROAP, which were highly expressed in most cancers and presented a strict positive correlation, led to a decreased life expectancy among cancer patients. ASPM and TROAP both regulated cell replication in the S&G2 phase of the cell cycle. Through a protein-protein interaction network (PPI) analysis of ASPM and TROAP, we found that cell division cycle 20 (CDC20) was regulated by TROAP and functioned upstream of ASPM. Thus, TROAP can regulate the role of ASPM in cancers. Conclusions: The ASPM and TROAP have a significant positive correlation and similar expression profiles, and promote tumor malignancy and development in the S&G2 phase of the cell cycle. Since ASPM is one of the downstream targets of TROAP, TROAP and especially ASPM may be potential tumor makers and promising targets for therapeutic strategy.

Methylation of PhoP by CheR Regulates Salmonella Virulence.

The two-component system PhoP/PhoQ is essential for Salmonella enterica serovar Typhimurium virulence. Here, we report that PhoP is methylated extensively. Two consecutive glutamate (E) and aspartate (D)/E residues, i.e., E8/D9 and E107/E108, and arginine (R) 112 can be methylated. Individual mutation of these above-mentioned residues caused impaired phosphorylation and dimerization or DNA-binding ability of PhoP to a different extent and led to attenuated bacterial virulence. With the help of specific antibodies recognizing methylated E8 and monomethylated R112, we found that the methylation levels of E8 or R112 decreased dramatically when bacteria encountered low magnesium, acidic pH, or phagocytosis by macrophages, under which PhoP can be activated. Furthermore, CheR, a bacterial chemotaxis methyltransferase, was identified to methylate R112. Overexpression of cheR decreased PhoP activity but increased PhoP stability. Together, the current study reveals that methylation plays an important role in regulating PhoP activities in response to environmental cues and, consequently, modulates Salmonella virulence. IMPORTANCE Posttranslational modifications (PTMs) play an important role in regulating enzyme activities, protein-protein interactions, or DNA-protein recognition and, consequently, modulate many biological functions. We demonstrated that PhoP, the response regulator of PhoP/PhoQ two-component system, could be methylated on several evolutionally conserved amino acid residues. These amino acid residues were crucial for PhoP phosphorylation or dimerization, DNA-binding ability of PhoP, and Salmonella virulence. Interestingly, methylation negatively regulated the activity of PhoP. A bacterial chemotaxis methyltransferase CheR was involved in PhoP methylation. Methylation of PhoP could stabilize it in an inactive conformation. Our work provides a more informative depiction of PhoP PTM and markedly improves our understanding of the coordinate regulation of bacterial chemotaxis and virulence.

The effectiveness and feasibility of fluid resuscitation directed by microcirculation monitoring in patients with septic shock: a randomized controlled trial.

BACKGROUND: This study sought to examine fluid resuscitation in septic shock patients by monitoring their sublabial point of care microcirculation score (POEM) scores (a 3.5 cut-off value was used as the end point of recovery). It also sought to explore the effectiveness and safety of using the POEM score in the fluid resuscitation of septic shock. METHODS: Patients were randomly allocated to the experimental group or the control group. In the experimental group, a POEM score >3 was used as the end point of fluid resuscitation. In the control group, the doctor just monitor, don't know the data. Patients' heart rates, mean arterial pressure (MAP), Acute Physiology and Chronic Health Disease Classification System II (APACHE II) scores, Sequential Organ Failure Assessment (SOFA) scores, and oxygenation index scores were recorded at 2, 24, 48, 72 h, and on the 7th day after admission to the study. Statistically significant differences between the 2 groups were examined. RESULTS: Thirty-one septic shock patients (comprising 14 patients in the experimental group and 17 patients in the control group) participated in our study. Patients' parameters upon admission to the study, including MAP, blood lactate and APACHE score, SOFA score, POEM score, cardiac output (CO), and central venous pressure (CVP), were recorded at 2 h; There was no significant difference in the APACHE II scores, SOFA scores, and oxygenation index scores at 48 h between the 2 groups; however, at 72 h, the scores of the experimental group were significantly better than those of the control group (P<0.05). CONCLUSIONS: Under the guidance of POEM scores, limited fluid resuscitation reduced the intake of fluid any unnecessary amounts of fluids. POEM scores also offered certain protective effects to organ function at the early stage of septic shock, and did not affect patients' circulation. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR2100049510).

Structural Basis for the C-Terminal Domain of Mycobacterium tuberculosis Ribosome Maturation Factor RimM to Bind Ribosomal Protein S19.

Multidrug-resistant tuberculosis (TB) is a serious threat to public health, calling for the development of new anti-TB drugs. Chaperon protein RimM, involved in the assembly of ribosomal protein S19 into 30S ribosomal subunit during ribosome maturation, is a potential drug target for TB treatment. The C-terminal domain (CTD) of RimM is primarily responsible for binding S19. However, both the CTD structure of RimM from Mycobacterium tuberculosis (MtbRimMCTD) and the molecular mechanisms underlying MtbRimMCTD binding S19 remain elusive. Here, we report the solution structure, dynamics features of MtbRimMCTD, and its interaction with S19. MtbRimMCTD has a rigid hydrophobic core comprised of a relatively conservative six-strand ß-barrel, tailed with a short α-helix and interspersed with flexible loops. Using several biophysical techniques including surface plasmon resonance (SPR) affinity assays, nuclear magnetic resonance (NMR) assays, and molecular docking, we established a structural model of the MtbRimMCTD-S19 complex and indicated that the ß4-ß5 loop and two nonconserved key residues (D105 and H129) significantly contributed to the unique pattern of MtbRimMCTD binding S19, which might be implicated in a form of orthogonality for species-dependent RimM-S19 interaction. Our study provides the structural basis for MtbRimMCTD binding S19 and is beneficial to the further exploration of MtbRimM as a potential target for the development of new anti-TB drugs.

The value of dynamic monitoring of procalcitonin in the early identification of pathogens and prognosis of bloodstream infections in the ICU.

BACKGROUND: To explore the value of dynamic monitoring of procalcitonin (PCT) for early identification of pathogens and prognosis of bloodstream infections (BSI) in the intensive care unit (ICU). METHODS: A retrospective analysis was performed on 84 patients with positive blood cultures. Patients were divided into the survival group and death group according to prognosis. Dynamic changes of PCT before and after treatment in the two groups were compared, as well as the relationship between such changes and prognosis. RESULTS: Among the 84 patients with bloodstream infections, 41 cases of Gram-negative (G-) bacteria, 40 cases of Gram-positive (G+) bacteria, and 3 cases of fungi were detected. PCT value in the G- bacteria group was significantly higher than that in the G+ bacteria group and fungus group, and the difference was statistically significant (P<0.05). PCT values on the first day of the G- bacteria group and the non-G- bacteria group were analyzed by a receiver operating characteristic (ROC) curve. When the threshold value was 3.84 ng/mL, the sensitivity, specificity, and area under the ROC curve for predicting G- bacteria bloodstream infection were 61%, 92.5%, and 0.841, respectively. The Kruskal-Wallis test (K-W test) was performed on PCT levels of each G- bacteria on the first day of bloodstream infection, and the difference was not statistically significant (P>0.05). Logistic binary regression analysis showed that the reduction rate of PCT after 5 days of treatment was an independent protective factor for patient survival. ROC curves showed that the sensitivity and specificity for predicting patient survival were 88% and 68.7%, respectively, when the PCT reduction rate (PCT(D1-D5)/D1) reached 36.02% or more. CONCLUSIONS: PCT can be used as an adjunctive method to quickly diagnose pathogenic microorganisms of bloodstream infections, and the anti-infection treatment scheme has certain guiding value. The dynamic changes in PCT have a certain role in predicting the therapeutic effect and prognosis of anti-infection treatment.

Heat shock protein 70 expression protects against sepsis-associated cardiomyopathy by inhibiting autophagy.

OBJECTIVES: Increasing evidence suggests that heat shock protein 70 (Hsp70) has a protective effect in sepsis-induced cardiomyopathy; however, the protective mechanism remains unclear. METHODS: Previous studies have also implicated autophagy in sepsis-induced cardiomyopathy. The aim of the current study was to reveal the protective mechanisms of Hsp70 in sepsis-induced cardiomyopathy using a cecal ligation and puncture (CLP) rat sepsis model. The roles of Hsp70 and autophagy in sepsis-induced cardiomyopathy were investigated by pretreating rats with the Hsp70 inhibitor quercetin or the autophagy inhibitor 3-methyladenine (3-Ma) before CLP. We also investigated the protective mechanisms of Hsp70 and the relationship between Hsp70 and autophagy in vitro by stimulating H9c2 cells with lipopolysaccharide (LPS) to simulate sepsis. RESULTS: The result show that inhibition of Hsp70 promoted sepsis-induced death in rats, while inhibition of autophagy inhibited sepsis-induced death. These results suggested that both Hsp70 and autophagy were involved in sepsis-induced cardiomyopathy. Overexpression of Hsp70 in H9c2 myocardial cells in vitro suppressed LPS-induced apoptosis, while inhibition of autophagy with 3-Ma also decreased LPS-induced H9c2 cell apoptosis, suggesting that the protective effect of Hsp70 in sepsis-induced cardiomyopathy was related to autophagy regulation. CONCLUSION: Overall, these results suggested that Hsp70 protected against sepsis-induced cardiac impairment by attenuating sepsis-induced autophagy.

Point-of-care microcirculation evaluated with sidestream dark field technology: agreement and comparison between sublingual and sublabial mucosa.

To investigate whether sublabial mucosa is more suitable for evaluation of microcirculation than commonly used sublingual mucosa in ICU patients, we enrolled 57 adults (47 critically ill patients and 10 volunteers) at convenience from Oct 2018 to Jan 2019. Videomicroscopy images at both sublingual mucosa and sublabial mucosa were acquired at the same time in each enrollee. Qualified images were recorded for later analysis. Four video clips of the same site were comprehensively evaluated to yield one Point Of carE Microcirculation (POEM) score by blinded investigator; POEM scores at both sites were statistically analyzed for correlation and agreement. Procedure time needed to acquire qualified images was also compared. POEM scores between the two sites showed no significant difference and a statistically significant correlation (Spearman correlation coefficient 0.716, P < 0.001). The intra-class correlation coefficient was 0.866 (95% C.I. 0.774, 0.921), suggesting good to excellent consistency and agreement between the POEM scores at the two sites. The procedure time needed to acquire 4 clips of qualified images at sublingual and sublabial sites were 10.5±3.9 minutes and 7.1±3.3 minutes respectively, P < 0.001. This study indicates that point of care evaluation of microcirculation by POEM score shows good to excellent agreement between sublingual mucosa and sublabial mucosa. It is easier to acquire qualified videomicroscopy images at sublabial mucosa than at sublingual mucosa. Therefore, sublabial mucosa might be more suitable for bedside evaluation of microcirculation with handheld SDF device in ICU.

[A case of large pulmonary embolism in trunk and branches with main manifestation of syncope, vomiting and shock].

OBJECTIVE: Pulmonary embolism (PE) refers to the endogenous or exogenous emboli blocking pulmonary trunk or branches, causing clinical and pathophysiological syndrome of pulmonary circulation disorder, the incidence rate is high. Sometimes PE patients were lack of specific symptoms and signs, or without any symptoms, which often result in misdiagnosis, un-timely diagnosis, and the delay of treatment. A PE case with syncope, vomiting and shock, which was proved to be pulmonary artery trunk and branch wide embolism later, was presented so as to improve the understanding of the disease.

Prognostic value of CD4(+)CD25(+) Tregs as a valuable biomarker for patients with sepsis in ICU.

BACKGROUND: Sepsis is a common complication of infections, burns, traumas, surgeries, poisonings, and post-cardiopulmonary resuscitation. The present study aimed to investigate prognostic value of CD4(+)CD25(+) regulatory T cells (Treg) in peripheral blood of patients with sepsis. METHODS: Periphery blood from 28 patients diagnosed with sepsis was collected on day 1 and 7 after hospitalization in the ICU of Shanghai Changzheng Hospital between December 2013 to April 2014. The blood was used for analyses of Treg ratio using flow cytometry and for analyses of blood routine test, C-reactive protein (CRP), bilirubin, procalcitonin (PCT), and coagulation. APACHE II and sequential organ failure assessment (SOFA) scores were also investigated. The results were compared between two outcome groups of survival or death to evaluate prognostic value for sepsis. RESULTS: The patients had an average age of 60.36±15.03 years, APACHE II score 16.68±7.00, and SOFA score 7.18±3.78. Among the 28 patients, 12 had severe trauma (42.9%), 10 had septic shock (35.7%), and 9 (32.2%) died. The median ratio of Tregs was 2.10% (0.80%, 3.10%) in the survival group vs. 1.80% (1.15%, 3.65%) in the death group (Z=-0.148, P=0.883) on day 1; however it was significantly changed to 0.90% (0.30%, 2.80%) vs. 5.70% (2.60%, 8.30%) (Z=-2.905, P=0.004). CONCLUSION: With better prospects for clinical application, dynamic monitoring of Tregs ratio in peripheral blood has potential value in predicting prognosis of sepsis.

[Synthesis and crystal structure of a porous coordination polymer [Nd2 (C6H8O4)3 (H2O)2]n x n (4,4'-bpy)].

A novel porous coordination polymer [Nd2 (C6H8O4)3 (H2O)2]n x n (4,4'-bpy) was synthesized by hydrothermal synthesis reaction of hexyl acid, 4,4'-bpy with NdCl3 x XH2O. The structure was characterized by elemental analysis, thermal gravimetric analysis, IR spectroscopy, and X-ray single crystal analysis. The crystal data are of an orthorhombic crystal system, Pbcn space group. Crystallographic data are: a = 2.201 2 nm(6), b = 0.777 8 nm(2), c = 1.972 4 nm(5), alpha = beta = gamma = 90 degrees, V = 337.70 nm(15)3, Z = 4, D(c) = 1.796 g x cm(-3), mu = 3.108 mm(-1), F(000) = 1 800, R = 0.043 0 and wR2 = 0.056 0. X-ray analysis reveals that three-dimensional porous nets were formed between Nd3+ and Nd3+ by carboxyl of hexyl acid.

Determination of mercury in biological tissues by graphite-furnace atomic absorption spectrometry with an in-situ concentration technique.

A method has been described for the determination of total mercury by graphite-furnace atomic absorption spectrometry (GFAAS) using an in-situ concentration technique with a Pd-Zr coating and a chemical modifier. The characteristic mass, which gives an integrated absorbance of 0.0044 s, was found to be 42 pg and an absolute detection limit (3sigma) of 33 pg was obtained with the proposed modifier. The total mercury values in standard reference materials, including Mussel (GBW08571), Bovine liver (GBW08306), Peach leaf (GBW08501) and Tea leaf (GBW080001), were determined using the proposed method, and the results were consistent with reference values. The method had been successfully applied to the determination of mercury in biological tissue samples with a recovery range of 94-105%.